1. Technical Field
The invention relates generally to emulating a hardware device, and more particularly, to a solution for replacing a hardware device with a combination of hardware and software.
2. Background Art
Frequently, as technology develops, an older hardware-based computing device (e.g., a legacy device) becomes outdated and is replaced by a new software-based computing solution. The new solution may provide increased flexibility, better performance, conform to modem standards/best practices, and/or the like. To this extent, the new solution will often reduce the overall cost of building and maintaining the computing infrastructure. In replacing the legacy device, it is desirable that existing software, such as one or more operating systems, that use the legacy device not require any modification. In particular, the new software-based solution should provide the same functionality and same communication interface to the existing software as that provided by the legacy device.
However, in some instances, all of the communication functionality provided by the legacy device cannot be replicated by software alone. For example, the 374x Communication Controller, a hardware control unit provided by International Business Machines Corp. of Armonk, N.Y. (IBM), provides support for enterprise systems connection (ESCON) channel connectivity using the channel data link control (CDLC) protocol for operating systems running on IBM's S/390 server platform. All of the communication functions provided by CDLC connectivity, such as hardware signaling (e.g., the creation of attention interrupts), cannot be achieved by software emulation alone. As a result, some combination of hardware and software will be required to provide the equivalent connectivity as that provided by the 374x Communication Controller.
To this extent, a need exists for a solution for emulating at least some of the communication functionality of a hardware device, such as a legacy hardware device, using a combination of hardware and software.